This article on new research that may explain how Avandia (rosiglitazone) degrades bone health has serious problems from the outset. The first sentence reads:
The popular diabetes drug marketed as Avandia may increase bone thinning, a discovery that could help explain why diabetics can have an increased risk of fractures.
Contrary to the first part of the sentence, previous research has already established that Avandia increases risk for osteoporosis. Contrary to the second part of the sentence, any link between the drug Avandia and osteoporosis could not explain the increased risk for osteoporosis faced by diabetics who are not taking the drug.
The description of Avandia is clinically incorrect. The article implies that it is used to augment the effect of insulin, suggesting that it is only for people who take insulin. Actually it is usually used in people with Type 2 without insulin. Probably what the author meant it that it augments the effectiveness of the patients’ "natural" insulin from their own pancreas. This is not clear.
The story fails to clarify two essential points:
The report does not interview independent experts in diabetes and osteoporosis treatment for insight into the clinical implications for humans taking Avandia.
The larger question here is whether this story should have been reported at all.
First, the published report itself is a letter, not a full research paper. Letters in journals are often not subjected to peer review. Journalists should think twice before writing about research based on a letter.
Further, at very best, this research sheds light on the physiological process behind a link that is already established. Even assuming that the findings apply to humans, the value of reporting them is not clear.
When health journalists write about studies done on animals, the bar for potential relevance should be set very high. This story does not pass over it.
Notwithstanding the fact that this report is about the observation of a process in a related species, quantifying the effect size with regard to harm in the mice would have been helpful. Were there twice as many fractures, 10 times as many, etc.?
The report is focused on the potential harms of rosiglitazone.
The study upon which this article was based is a laboratory observation of mice. The article should have said this plainly and from the beginning, and warned readers that findings from experiments on animals do not necessarily apply to humans.
Further, the publication in Nature Medicine appeared as a "letter," not a full research paper. This too is a lower level of evidence.
The article does nothing to exaggerate the seriousness of diabetes or osteoporosis. But there also is no estimate of how often fractures happen for persons in general in this age group and for persons on this medication. Some estimate of how much the fracture risk is increased by Avandia would have been a good addition since patients need to weigh the potential risks and benefits of any medication.
The published source, a research letter based on mouse modeling, falls far short of a gold-standard clinical trial in humans.
The only source interviewed about the findings is the study’s lead author.
The article does not mention that there are many alternative drug treatments for type 2 diabetes. Given the fear the article may provoke, this is a key oversight.
The article correctly describes Avandia (rosiglitazone) as popular and widely used. Stating the number of users or prescriptions written would have been useful.
The article’s first paragraph implies that a link between rosiglitazone and osteoporosis has just been discovered. This link was established in previous research.
What’s new here is a possible explanation of how the drug affects the bone-building process. The article does not make this clear.
Because the only person interviewed was the study’s lead author, we can’t be sure if it relied solely or largely on a news release.